Further Baseline Studies to Assess Onshore Oil & Gas Risks to Groundwater

Aquifers of England with prospective areas for onshore oil and gas activities.

BGS and the Environment Agency are collaborating in a project to characterise groundwater quality to support assessment of the risks to groundwater in England from any new developments in activities related to onshore oil and gas, including shale gas. The project will last for three years, from November 2018.

Rationale

Establishing a good baseline for groundwater quality ahead of any onshore oil and gas development is essential for helping to identify future changes that may occur as a result of new activities. Past monitoring has shown that a range of substances that could be associated with new oil and gas activities may already exist in a variety of groundwater circumstances. This may be because they occur naturally or they could result from earlier anthropogenic sources.

BGS carried out investigations of the quality of groundwater in aquifers of England and Wales between the late 1990s and 2015. Part of this investigation includes a series of 23 reports and an overall synthesis report, in a collaboration between BGS and the Environment Agency which took place between 2002 and 2005. BGS’s own baseline investigations both pre– and post–dated this collaboration. The studies were designed to provide a wide–ranging understanding of baseline groundwater quality across the country. Although comprehensive, in the context of our nascent onshore oil and gas industry, methane and hydrocarbons were not generally included in these baseline reports. BGS, again with EA support, has also carried out an initial survey of methane in aquifer. However, a further evaluation of groundwater quality including relevant hydrocarbons is needed for a thorough understanding of the groundwater baseline in the oil and gas industry context.

Activities

This new study will review existing data for relevant aquifers in England (in relation to onshore oil and gas exploration) and will involve further groundwater sampling. Sampling will focus on areas/aquifers not included in previous baseline studies, including minor aquifers, but will also be carried out in aquifers considered previously where relevant. The geological and soil conditions that may give rise to the presence of substances associated with onshore oil and gas will also be characterised (e.g. the impact of proximity to methane–bearing media such as coal measures and peat soils).

Activities will include:

  • review of existing regional data to ascertain available information on oil and gas type substances and distributions
  • sampling and analysis of groundwater from potential oil and gas exploration areas to provide a more comprehensive dataset
  • determination of regional baseline conditions for methane in groundwater, along with other relevant oil–and–gas–related parameter
  • characterisation of strata that act as sources for substances of potential concern, based on hydrogeological conceptualisation
  • extrapolation of findings to other aquifers in proximity to potential new oil and gas activities
  • presentation of findings and summary data.

Sampling and analysis

Evaluation of groundwater quality has begun with a pilot study in the Sherwood Sandstone aquifer of north Nottinghamshire and south Yorkshire. Sampling and analysis of groundwater for this area has begun (Spring 2019) and preliminary findings are under investigation.


Contact

Contact BGS enquiries for further information.